Fuel-feeding- device



C. S. HEFFELFI'NGEH. FUEL FEEDING DEVICE. APPLICATION FILED JUNE 2, 1914A l 1,304,973-, Paf-@med May 27,1919, 2 SHEETS-SHEET l.

M ww iwf@ @Qi 2 SHEETS-SHEET 2.

C. S. HEFFELFINGER.

FUEL FEEDING DEVICEA APPLICATION FILED JUNE 2, 1914.

NMi/252mm f,

' CHARLES s. Hnrrnarruenn, or anreisen, rnnnsrnrnnrs,

FUEL-Fenomennvron.

To all whom-t may concern.'

' Be it known that I, CHARLES S. Herran- FINGER, a citizen of the United States, residing atLebanon, `in the county of Lebanon and State" of Pennsylvania, have invented certain' .new and useful Improvements in' Fuel-Feeding Devices, of which the follow'- ing is aspecilication.

yso

' and controlling the feed of powdereolfuelto This invention relates to fuel feedingrdevices; and' it relates more particularly to apparatus for feedin commi'uuted or powderedvssolid fuelto a 11 ratus comprising conveyer means arranged to convey` eomminuted fuel in regulable quantity from a source of supply to a point, lof use, means for utilirling the fuel thus conveyed', 'and means most advantageously coaxia'lwith said conveyor meansfor returning thereto any unusedportions of the fuel.. 'lhe nature ofthe invention is more fullyset forth in the accompanying descriptionand claims and in hereof.-

Fuel burners employin mixtures of air with powdered coal or the ike are commonlyused `1n many types of lcombustion apparatus such -as furnaces of various kinds, rotary cement kilns, etc.; and within certain limits they have proyed'` .fairly satisfactory in practice; Considerable difficulty has been experienced, however, in accurately regulating the burner` or other combustion means so as to insure uniform Acharacter of the' `combustion fiume under constant given' conditions of operation,y and also to provide for suitable variation in the character of the flame Withinlimits, something which is often necessary in practice. -Suitable disposition of the f'coarserf particles l,of fuel which invariably accompany the powdered fuel 'and which are toocoarse toybe advantageously fed directly i to a powdered fuel burner, is another seri- I the' difficulties a ous problem whichfhas not heretofore been satisfactorily solved.

One ofthe principal objects of the present invention is toI rvide apparatus in which ve noted are avoided and sundry new advantages are attained. By means of the' novel apparatus hereinafter disclosed the character of the mixture supplied to the combustionburner may be maintained substantially/uniform for any given conditions of operation; orlitina be varied at will to give'cornbustion'ames iffering as widely in character as the requirements of Specification of Letters Patent.

el burner, said appa# i the drawings forming a part ing such' that such Patenten may at., raie,

Application ledl June 2, 1914. Serial No. 842,3823.

the particular work in hand may call for. Another object ofthe invention is to insure that. particles of fuel which lijf-reason ot their` coarseness normally do not passd a' given point in the apparatus are systematically i' caused to be again acted upon by the feed ing device and to be furtherv comminuted;l thereby to a greater or less extent.. Another object of the invention is to provide apparatusof-this character which is simple and conipactin form, is economical of ower, andA which vwill operate successfully with little or no attention from an attendant over long periods of time. @ther objects of the inventlon will appear as the description proceeds.- Y.

, Briefly described, the complete -apparatus of the present invention in its best form comprisesy regulable eonveyer4 means for transferring comminuted fuel from a source l of supply to ga pointof discharge from which the finer portions of the fuel are transported in a state of suspension, as by a current of a gas which is commonly air, to a suitable combustion device. Means are also .best provided for trapping or retaining any rela.- y

tively coarse fuel particles discharged by the conveyer means and for returning-them to the lconveyer means, the arrangement bearticles undergo more or less further comminution in the course of their ,return to and re-passage through the conveyor, and are thus eventually reduced for the most part to a suiicient degree of fineness to be carried od by the air current.

The arran ementherein disclosed for returning coars. fuel particles tothe afore-` said conveyor means, which may conven-4 iently be termed the lprimary conveyer means, constitutes an important feature of the invention. In its best embodiment this arrangement comprises J'returnlng means or secondary conveyer means integral with-or y conveyor. The apparatus of the present in venton enables marked saving 1n power over its Such arrangements, besides makingr for corn.

the embsdimet he? Snown is mazze'y one example of fa/ppmi'zttus commg Wlthm the.

ew of the invention; und that th i11- "veutlm by no means mte to @fue Specic @,'angel'gant of the @Jpgamtus pruts heg@ shown.

tion si:

sectmn maken @in im@ 'o sida View ou L :L suctfm tan w; 1 .cal form Y '5. S lschzu'ge being; show;

- s dta section thm-ugh to cwmbustgi@ fumata, 01:1 sn'mler a t ma slmm View off the @Dawg/e1:

'to the nirfmmgfsj L o? @that Satire@ Q: f t

ayu' lm/ice amt the any yq. a

. which is secmf,

`mim :invent to the ing upright lo'. :it wil two sets of comeyar cl'ectmns.

giving them a, Somewhat gr atta; pltch the threads of the out-3' convoy/fl nis compound Cont/cya? miambw may "manuvzt' ino ugh obvioutta il, Sam@ into one cm1; @ifm Enablingrecaer/a conduit l0 through which4 comminuted fuel is carried from the conveyer by the fuelc-ntraining air current. yHand-holes Lll may be provided to enable ready inspection of the interior ofthe chamber and the removal.-

- therefrom of accumulated foreign material lll Achamber E20, bends upward suddenly, a porL tion l2 thereof extending vertically and conetituting a trap or separator in which the carser particles of fuel', which may be carried along with the air current trom the ,ffc'onveyer, have an opportunity to settle out nby gravity. Such particles are deposited at Llll lill

'Eli

till

:all

' the lower end of the conduit andwork their way back into chamber.20 where they are directed' by, the pilot screw conveyer into vthe return conveyor which carries them to the other end of the apparatus and delivers them through openings 34C to the exterior or primary conveyer. After extending verticallyfor some distance as described, the conduit leads to the intake i3 of a suction or vacuum producing apparatus such as a centrifugal fan or blower lll which discharges through conduit connections l5 and 46. The mixture of air and powdered fuel discharged from. the 'blower may be consumed in any suitable type of combustion apparatus. ln the present instance is illustrated an arrangement in which lthe powdered coal is blown into a supplemental air conduit a? entering the wall 48 of a furnace. Preheated air may be supplied through conduit l? in amounts regulable by means of valve or damper 49 to form'with the powdered fuel blast a combustible mixture of any desired composition.

ln Figs. d and 5 a preferred construction of fthe fan is clearly illustrated. The vanes of the fan or blower are best bent as at 50 to formiliftingpockets and to engage more or less tangentially a supporting cone or hub l secured to shaft 52 which may be driven by a variable speed motor This conical hub is located opposite the axial intake opening,` 43 of the fan rotor, and it therefore serves as a shield to protect the bearing 54 of the fan shaft from the finely divided fuel drawn in with air through the fan inlet. Discharge conduit connections 45, 46, may include a -way coupling meinber 55 at which point an auxiliary air conduit may be connected if desired, one opening,` in the coupling being closed in the present example as by a plug 56. More than one such set of connections may, of course,

j beconnected to the discharge of the blower,

the present arrangement being merely typr' cal. I t i For the purpose of regulating the quan tity of mixture passing into the conduit 40,

the conical chamber may be provided at its smaller end with valve head 57 carrie by a valve stem 5:8 which' passes through the Wall of conduit and is threaded to engage a threaded bossI 59. By suitably manipulating a controllin handle 60 on the valve stein, the valve hea may be moved awayY from or toward the,

small end of the chamber 20, thus varying within any desired limits the width of the annular space between the valve head and the Walls of chamber 20, and in this way regulating the amount of mixture passing therethrough. 4ln the present example the valve head is shown as somewhat smaller than the smallest-diameter of chamber 20, so that the outlet can not be closed by said valve head. This arrangement is" not essential, however, and the valve head ma be arranged to entirely close the outlet yif dealve means such as a sired. Moreover, it is not absolutely nec? essary to provide regulating valve means f any description' at this location, since' efficient'control can be otherwise attained as,

for example, by varying the speed of motorA 53. The arrangement described isconvenient, however, and provides an additional refinement in control. If desired, conduit 40 may also be provided at any convenient point with a valved inlet 47 whereby additional air may be drawn in if .it is advisable at any-time to supply a particularly lean mixture to the combustion burner.

ln the arrangement here described, the fuel coming from the feed hopper is subjected to an air current induced by suction of a fan, that is, toa current of 'air under reduced pressure. Ordinarily "the air 'assing into the casing with the fuel going A'rom thc feed hopper is sufficient in' quantity 4for the purposes of Jdie invention. It -isobvious that supplementary air inlets,l best Con- 'i trollod by valve means of Some kind, may be provided 1n the coiivcyer' casing at any convenient location, or in other parts of the ap- K paratus adjacent thereto, as foil` example, in.I

v Although the use of an induced or reduced pressure draft is disthe feed hopper.

tinctly advantageous, ,the invention is not lio restricted thereto, and forced draft under any suitable degree of pressure may be employed 11i modified forms of the where desirable.'

,The operation of theapparatus above. de

scribed 'is sufficiently obvious from the foregoing. The motor 53 being suitably ener'- `rif/2cd, and the conveyer shell being' revolvedapparatus in the proper direction, fuel passes from the feed hopper into the conveyer casing where'- upoii it is moved toward the left at any desired rate of speed by the outer spiral ,conJ veyer blades. l By the suction of the fan lair is drawn into the couveycr casing from the feed hopper or other suitable source; and

` this; returned iiiaterizil mi 'wel 'the i'i eff iiiie ySurface of 'the conveyei shell,

r `becomes suiicieutly line te .ef the cenveyei'.

.v i ..ii' passes in cominci with th siihsi'imizaly giu-allel to its come@ towwfl chamber 20. More ci l, pnesesjbhioiigh poits 3% of the e0 :mol along the iimei' sul" Convey/31j shell. This induced pas thi-nigh 'the cenical euhlet c fuel mici d en its Way ai' also shell. "ice of the ai? uiieiit ef chamhei '20,' cum-ying with it, in Suspension the lirici pai-hides 0f fuel' supplied te the chamhe hy 'the i'ei'ol'ulele conveyei. The zur cm'eii' after leaving; chamber :'20 :es Suilileiily direc' he aix comliii; mil clmfiiig this priei elf its travel, the comhnsilile mixture rec. of a large @zich of whatever unclesif comse fuel' pzu'lielee may have been. car 1c by the niicurve/nib from climibei' 20. "mies poiien of the mixture. cei'iclui; ther/foie serves n, kind of tmp oisepzwitoif 'in which the umlesii'zishly eeuwse fuel 'particles :we grm'imlly eliminated 'i'oui iihe m'lm'gure, falling hack :i 1d-collecting); in chaiil'iei These trapped 0i' returned Yfuel particles are .directed hrmigh the agency 'the pil@ lli'. is to be noted, chle iii the specific embodiment here illuemucil. ighci'e is 'thus imiinivained :i ciyxciilziticn of fuel iii a cil'ciiit. mul that he 'fuel muy he subjected m the influence of au air current ab ihsbeiitizilly all poiu's in chia ciircuit or over am extensive pm 'imi ihexeef.

AS v. iesuli'., the siii' euienfu imnuveS finely iliviilecl, pi'ticlcs from the i'ucl o a1 gremjei m: less ement het only at. the poin'. of ciscli-.uge into chamber 20., bul also fe 5eme ciment lzhi'eughout smh stanti-ally the entire eii'cui. in which ihe iuel being; move l l J. The cute? and inner Spu'm convey we while designed te eperwbe :Siziii lacet o she casing and ci? folie stationery @heft iesapeetivcly7 7 may iieverhcless periiii; paris; seme im together with :seme eid che mere Finely tlivide-il fuel. The major peitieii of the siii* eiiii'ei'i'; follw'ws Hiv sph-hl ci: the l thx'mig the ciiiixf'e'yei.. ligi 'l ik y divided fuel te che cumfen-is 'ieiii'leieii sahetmiielly imioin for any given @penning speed el' libhe Suc ion imi und The fuel-laden. nii* :i'fei" passing "che vertical pm tion o' the conduit 42 is drawn into *the fm1 inlet and is alisclizugeil 'from the fau casing under gi'essuie uml pzieses h y Vey of the discharge conneci the" particule? 'faim means for .accomplish tions 0 u mwlcreil fuel hmiie ffii my .nary er suit'zlhle deeign.

The @changement of compound conve meer@ mizuigeil ce-.lxially Oneivithii other :is herev illusmei, l; consider a, v Vf iuipei'mnib ezitme @if the iiweniien, both enhances the imiiermity elf fuel fl :iml cmisequently @if mixture composiieii. of the invention h i-showiig and .fuifhei because il', i'eeiiii's in very ceiilpzict fe n @ii construccion, e 'l el coiistiuccien mcieovei which very imM 'ple economical of pewei" encl inexjeiisie hoch in iiiet cosi; amd in irminzteuaiice.

believe it te be broadly new im zeppa? rati" eeciiiig' fuel, "ce fuel hu pim'iiile coiiif'eycir iii-ens elf the Wwe. h #ein il dfi disWis ci l :ended ene vri'ihin bhe cth` provide :i ceili'eye i with siiiul. 0i sc blades m its einer and inner Suifzicee, che spirals being arranged. m

pps-,mms helfe ilii i izieehziiiiezil de" iiliile .st-ill rewiiniiig me principal :Le tug-eSiulici-en inthe bi'oeili.' i iiicengicn and. Such a. I 5 4 mmm 'me rope @i th IFT A T w.' heb i.

l. nel

claim iff-- Feeding; :i

means foi: conv-yin pa 'mais @empf amount lil-,em Seuicc 0;. supply 'te e mim o ilirschzire? mamie 01 subie iig the ills Y iiicliiccd nii' ufl eL ppm i'ufs, c "V ceinliiiiagicna "mah mezuis im* sin`^ `gli, ai iiiiiiiiteclj fuel., :m'emluble ce Neyer," l e zu'ieugcil i'zmslei' 'fuel thug-ehem :i @sinh o clieeliau'ge, ineens fieiisiihim che ci fuel 'a euri. ii-l; of ai. scemi@ veluhle eciweyer iiieiiihe siam ci' axial Wiibh ille lli:

yincarne.

' 'and ri id therewith for returning to the latter fuel discharged thereby but not caru ried awa bythe air current.

5. ue feeding apparatus comprising the combination, with `a'supply hopper for comininuted fuel, of 'a spiral conveyor arranged to transfer' fuel therefrom to a point of discharge, meansfr subjecting the discharged fuel to acurrent of air, a second spiral conveyer 'substantially coaxial with the first for returning to the latter fuel discharged thereby but not carried away by the air current, and means for facilitatingl feeding of such fuel to said second conveyer.

6. ln fuel feeding apparatus, the comb-ination, with a conveyer, a chamber into which said conveyor yis arranged to discharge connninuted fuel., and means for removing fuel from said chamber for use, of a second conveyer arranged to transfer resid-y ual fuel from said chamber to the first conveyor, and means for facilitating feeding of such residual fuel to the second conve er.

lin fuel feeding apparatus, the combination, with a screw or spiral conveyer, a casing into which said conveyer is arranged to discharge comminuted fuel, of a second screw or spiral conveyer substantially coaxial with the rst and arranged to return fuel from said casing to the first oonveyer, and a ilot or auxiliary conveyer arranged to gui e fuel to said second conveyer.

8. Fuel feeding apparatus comprising l' means foreirculating comminuted fuel in 'a circuit, rneansfor supplying fuel to such `circulating means, and means for passing a lfuel.-entraining current of air' in contact with such circulating means and with the fuel being moved thereby substantially throughout the entire circuit and beyond such circuit in the same general direction,

and means for utilizing the fuel-laden air thus obtained.

9. Fuel jleedino apparatus comprlsin a l hopper for' supplying comminuted fue 4a 'Bil conveyer' casing arranged to receive fuel from said hopper, compound conveyor means arranged to maintain' continuous circulation of fuel within said casing, and means for passing a fuel-entraining current of air through said casing in contact with such fuel and substantially parallel to its course, in combinationl with means for utilizing the fuel-laden air thus obtained.

10. Fuel feeding apparatus comprising the combination, with comminuted fuel supply means, of a casing arranged to receive `fuel therefrom, a hollow cylindrical device mounted to revolve wi'hin said casing, spiral conveyor blades on the outer surface of xsaid device 4arranged to feed fuel from the supply fuoans'to Va point of discharge, moans for subjecting the discharged fuel to a current of air, means adjacent the point of discharge for feeding into the interior of said conveyer device residual fuel not carried away by the airl current,` and spiral conveyer blades on the interior of said device arranged to return such residual fuel to the outer' conveyor blades.

11. Fuel feeding apparatus comprising the combination with comminutcd fuel supply'means of a casing adapted to receive fuel therefrom, a hollow cylindrical member or, shell revolubly supported .within said shell, said casing being provided exteriorly with spiral conveyor blades arranged to .move fuel from the supply means to a point of discharge and'interiorly with spiral convveyer blades arranged-'in an 'opposite sense,

means for revolving said shell, a discharge chamber arranged to receive fuel discharged by the exterior conveyor blades, a fan. arranged to draw airthrough said discharge chamber, and auxiliary conveyor means 4revoluble with`said shell and extending into the discharge chamber for directing 'residual fuel from said chamber to the'interior conveyer blades, the latter being arrangedl to move such fuel toward the other end of the shell and to deliver it to the exterior conveyer blades.

l2. Fuel feeding apparatus, comprising the combination, with fuel supply means, of conveyers disposed substantially one within the other, one of saidi-conveyers being arranged to feed fuel from the supply means" to a point of discharge,y and means for subjecting fuel discharged from' said conveyer to an air current to remove at least a part of such fuel, anotherof said conveyers being arranged to return to the first' conveyor residual fuel not removed by the air current.

13. Fuel feeding apparatus compri-sing the combination with a casing provided with-` vided material, the combination of a. maga-` zine, a hollow feed screw extending through.

and out of said magazine, means for passing a current of air through said hollow screw to the outer end thereof, and means for returning to the magazine the surplus material not picked up by the air current.

15.. ln an `apparatus for feeding finely divided material, the combination of a maga` zine, a hollow feed `screw extending through and out of seid magazine, means for passing a cui'i'eilt 0i mii? iiiiough Szi'i bellow sc'ew to the, miti-xi: and iieieof, a L mams i101' turning to che magazine the surplus manic iaino picid up. by *mha ail' current, said meanswmpiising :i i-etui'u screw located Q ,ieli@ i'ieeed sci'ewand extending bwii is dia magazine,

)the circuit,

supplying Cmmiiimltu. iuel :uid [maiis :'foiipnssing si, cmfient iii cm'rtact wiih such incl @ver a Subs Mumien 0i' dife cibi-cuit and boyoiifi sii h circuit in the same gmiemi difecbimi, it@ Obtain a inimlie 0i ai?? and fuel suitable fm; combustion puiposes,

1'?. Fuel feeding' fippumiu comprising i'ei'oiubie vcmweyi iiiuzu capable of moving cmmninu'ted salici fusi in 5L circuit, means for supplying commiiiutd fuel 'to the ciiciilitv and means 'for passing@ Current of air iii com met with such iuci and Substantially parai- Lel tothe-iiiiection of fusi tim/ei @ver u sub- S'tantiai portion of the circuit, to obtain :i

mixture of ai und fuel suitable for cmubustion puiposea Enf-ii feeding :ipj Matus Comui'ising a primary convey@ :wiiuiged "a0 move :Enel from :1. SOL me 0i' supply tov a point oi fis- Chaig'c, means for iiifjc'ing h@ fiischm'ged fuel L u @armuto' nir7 and a secondmy Crm- Veyer zimnged to reim-n tu the pi'imniy @oir Veyei' iesiuii iin-@i not Carried away by the air muren@ sziifi conveyors being; combined in agffibs'antially unitmfy coiweyei struc t1i1c,m1d means for opeming said. conv siieii and :ii mici sciwoyf inambei' by mi air clim-@im )Fuel feeding zippaizzi hoiim* c-yliiidiieai simil im, @Xieiioi' 0f @mix/Wer ing arrange-,ci t@ nieve ma. diiecims., a casini win is remiiuisiy morini' i 'fuel in@ said i 'i miwoyei bimls 1 1 n'xeims 11301' Supplying i gy @ne Sei; of

and die D 1 (fir in Said Sheii thfe'xi' first-'mined Set 0 Conv@ .in i165* mmy whereof ha" speciiicatwn in in@ pisse/nce 0i" Bmwin 

